Efforts to control the ownership and use of guns have posed a legal and social challenge. Regulating the use of guns, in particular loaded guns, poses challenges in America. In many other countries the right to own and use a firearm is severely curtailed or even absent. In the United States, on the other hand, the right to bear arms guaranteed in the Constitution precludes outright right regulation of firearms to the extent of depriving most citizens of firearms. While many folks insist on responsibly using their guns in hunting and self-defense, the availability of guns empowers others to commit crimes. There is no way to a priori distinguish between the two types of individuals. The US Constitution assures due process and precludes prejudging a person as being a threat to society absent some overt act or indication. Add to the mix the expectation of not being unreasonably searched, and one has the mix for making possible mass shootings, rage killings, and firearm accidents.
Since, some policies adopted in foreign jurisdictions with low gun violence—the banning of gun ownership—are not practical in jurisdictions like the United States, there are no good answers. The measures adopted so far, such as profiling based on race, gender and ethnicity run, if implemented sufficiently generously, afoul of other Constitutional assurances. As a result the first intimation of a shooter is when the shooting has already started. Despite this reality, reducing gun violence to improve public safety presents a long-standing unmet need.
Just about every functional gun poses the risk of violence—provided it is loaded. Conventional cartridges for rifles and machine guns, as well as larger caliber weapons are usually made with brass casings or composite casings that include metal, plastic, paper or combinations thereof. The casing includes an integrally formed head containing a primer cup to receive a primer adapted to ignite a charge at one end, and at the other end provides a mechanical fit to a bullet. The grip of the cartridge upon the bullet, together with the amount and characteristics of the powder/charge, the interior volume of the powder chamber and other factors determine the chamber pressure levels developed during the firing cycle. The bullet or other projectile is held in place with a crimp or frictional engagement, the strength of which is a factor in determining the pressure needed to initiate bullet movement into the barrel of the rifle.
Cartridges are typically made with bullets in metal casing. Shot gun cartridges may have paper or plastic shell casings. It has been known to make shell casings with materials such as plastic, which provide less shielding against electromagnetic signal reception and transmission compared to metal casings. U.S. Pat. No. 2,654,319 discloses a sectional cartridge including a plastic shell that will be converted to gas during the firing phase to assist in propelling the projectile and thereby permit reduction in the use of the propelling powder charge. U.S. Pat. No. 3,026,802 discloses a cartridge made using light weight thermoplastic materials. U.S. Pat. No. 3,745,924 discloses a plastic cartridge whose ballistics are equivalent to existing metallic cartridges and which can be fired in existing firearms. U.S. Pat. No. 3,842,739 discloses a plastic cartridge with a cartridge case having a plastic body has a metallic tubular mouth member affixed thereto, which may be crimped to securely hold a projectile. U.S. Pat. No. 3,874,294 discloses a center fire cartridge case for high pressure cartridges with a plastic body and a metallic head. U.S. Pat. No. 3,977,326 discloses a composite cartridge casing having a plurality of component parts, which may be of dissimilar materials such as metal and plastic.
There are additional patents that teach the making of hybrid cartridges that have non-shielding materials as part of their body, which improves transmission of electromagnetic signals. For instance, U.S. Pat. No. 3,952,657 discloses plastic shell receiving a propellant charge with even the cartridge being expelled by the ignited gases from a rifle to approximate a shell-less cartridge. U.S. Pat. No. 4,147,107 discloses plastic shell with a metal bottom that is suitable for rifles. The'107 patent explains that the “use of a plastics material for ammunition cartridge cases offers considerable advantages over usual metal cases in regard to cost and production, but necessitates a bottom insert of metal which is suitable as a groove or edge for engaging the usual cartridge extractor and ejector and for receiving and holding a detonator or percussion cap”. U.S. Pat. No. 5,151,555 discloses plastic cartridges suitable for rapid-fire weapons. The '555 patent's disclosed cartridge has a plastic case with a pressure regulating baffle or wall. The '555 patent teaches that a plastic rifle cartridge should have a metal cap or head to carry the primer and to provide the ejection groove necessary to eject the spent cartridge from the firing chamber. When used in a modern automatic weapon the need is also present for a reinforced cap or head area to contain residual pressures in the cartridge occasionally encountered when the ejection cycle begins removal of the cartridge from the chamber before the pressure effects of the recent firing have fully dissipated. U.S. Pat. No. 8,186,273 discloses that plastic casings for ammunition may be made using injection molding processes for combat ammunition, target ammunition and blanks.
There are patents describing the improvements and variant ammunition designs that modify the primer or the bullet part of a piece of ammunition or both to achieve delayed detonation of some part of the charge such as U.S. Pat. No. 4,216,722 disclosing an exploding bullet with more than one primer portion built therein. U.S. Pat. No. 4,222,330 describes cartridge ammunition with known magnetic tags for identification therein for rifles and pistols, particularly for civilian use. Ammunition is of two basic types: center-fire and rimfire. The projectile portion is fitted into a casing portion. An explosive material, such as smokeless gunpower, is disposed within the casing and sealed therein by the projectile portion of the cartridge. Additionally, in center-fire ammunition there is disposed a primer located at the end of the casing opposite the open end into which the projectile is fitted. The primer comprises a primer case and a primer explosive which is typically detonated by the impact of a firing pin on the primer case. Thus, in center-fire ammunition cartridges, the detonation of the primer acts to detonate the main explosive powder charge which accelerates the projectile along the barrel of the rifle or pistol into which the cartridge has been inserted. Rimfire ammunition cartridges work in the same way except that the primer explosive is not centrally located and typically is not disposed in its own casing. The presence or absence of magnetic particles with defined Curie temperatures allows tagging of the ammunition to identify it after the firing of the ammunition.
U.S. Pat. No. 4,009,060 describes a shapeable primer composition that can be solidified from a melt state into a solid of a desired shape. It should be noted that there are many additional primer compositions known that provide other benefits from prolonged lifetimes to other detonation related parameters. U.S. Pat. No. 4,142,441 describes a primer seating tool for centerfire cartridges. U.S. Pat. No. 4,189,980 describes a method and device for reloading a centerfire cartridge. U.S. Pat. No. 4,149,465 describes an improved ammunition cartridge with modifications to the primer portion.
One way to limit firearm mediated violence is to introduce identification tools to allow quick identification of perpetrators to dissuade violent acts. Many identification devices and methods of making them for use with firearms are known. In particular, it is known how to identify retail purchasers of ammunition cartridges and even the bullets within them. Typically a physically readable mark serves as an identifier, which mark is placed either directly on the bullet, on a casing of a bullet, or on a barrel of a gun. In addition there are devices that can store information about a buyer or handler of ammunition in an electronic memory in the cartridge—as is described, for instance in U.S. Pat. No. 7,533,614. Many additional identification strategies are disclosed in U.S. Pat. Nos. 6,293,204; 6,462,302; and 6,886,284. This list is not exhaustive with many ways to mark a serial number and the like proposed over time.
Such tracking of buyers or possessors of ammunition in a database is difficult to manage, and raises privacy concerns. Another limitation is that it is more difficult to effectively manage distinct identifiers, as they are constrained by the physical limitations of the bullet surface on which marking can occur. Still another significant limitation is that by applying different marks to munitions cartridges requires changing the manner in which such ammunition cartridges are made from a bulk manufacturing process, in which all ammunition cartridges are made the same way, to a batch manufacturing process, in which different batches of ammunition cartridges are made (such as divided by the box size of the ammunition cartridge), in order apply a different identifier to all the ammunition cartridges in a single box.
But even more significantly being able to track the last buyer or possessor of ammunition is of little use in preventing accidental or deliberate incidents and the problem of minimizing or at least reducing undesirable gun violence remains unsolved.